Squeeze presses are widely used in the foundry industry in the production of green sand molds each comprising a cope and drag. In a typical squeeze press, a metal pattern corresponding to the particular cope or drag to be produced is supported on a support plate atop a jolt table, a mold flask is positioned about the pattern and loose foundry sand is introduced into the mold flask about the pattern. The squeeze press includes a vertically movable bolster located above the work station for carrying a sand-forming tool (referred to by some as a squeeze board) specially configured or matched to the particular pattern in the mold flask so as to compress the loose sand uniformly about the pattern by downward movement of the bolster. The use of matched pattern/squeeze board sets results in more uniform compaction of the loose sand about the particular pattern and in the production of more uniformly dimensioned molds. Improvements in dimensional control of the sand molds translates into corresponding improvements in the metal castings made in those molds.
During the production of sand molds using matched pattern/squeeze board sets, the squeeze press is stopped whenever a different sand mold (e.g., cope or drag) is to be produced during a production run in order to replace one pattern and squeeze board set with another set. In the past, replacement of the squeeze board has been a tedious and time-consuming operation in that numerous fasteners (e.g., machine screws) holding the squeeze board to the bolster must be manually removed to free the squeeze board for removal and replacement with another squeeze board that is matched to the particular replacement pattern to be positioned on the jolt table. The replacement squeeze board must then be fastened to the bolster in still another tedious and time-consuming manual operation.
As a result, there is a need to facilitate replacement of one squeeze board with another during a production run of sand molds. In particular, there is a need to reduce the manual labor and time involved in replacing one squeeze board for another on the bolster of the squeeze press while still insuring that the squeeze board is firmly secured to the bolster.
It is an object of the invention to satisfy this need as it relates particularly to foundry squeeze presses and as it relates more generally to other presses where more rapid change-over from one forming tool to another during a production run is desired.
It is another object of the invention to provide a forming press of the type having a bolster and a forming tool secured thereagainst wherein a "quick-change" tool-to-bolster locking mechanism is provided to facilitate change-over from one forming tool to another.
It is another object of the invention to provide a forming press of the type having a bolster and a forming tool secured thereagainst using a "quick-change" tool-to-bolster locking mechanism comprising a particular arrangement of hooks on the bolster and trunnions on the forming tool that are engageable in such a manner as to releasably secure the tool against the bolster and are readily disengageable in such a manner as to quickly free the forming tool for replacement with another tool.